ButtKicker BK-LINK RF Wireless System (Discontinued by Manufacturer) Allow your ButtKicker LFE unit to communicate via RF radio frequency with the rest of your audio system Expand ButtKicker LFE locations and remove the unsightly tangle of connecting wires Set-up is simple, with transmitter and receiver attaching via standard RCA cables Can communicate over several dozen feet even through walls and ceilings Operates on the 900 MHz bandwidth with a frequency range of 5 to 350 MHz